Canon USM vs STM lens
28962
STM stands for Stepper Motor and is a applied to a new range of Canon lenses which feature a new design of focus motors which, along with a new iris mechanism are designed to eliminate (auditory) noise during video recording. Canon haven't revealed any information about how the new design works but it's probably the same type of motor used in mirrorless camera lenses. It's a more precise version of a regular DC motor but still has the same direct connection to the lens focus group, which means manual focus has to be implemented using a focus-by-wire arrangement whereby moving the focus ring by hand sends a signal to the motor to move the focus group. In comparison an ultrasonic motor (like Canon's USM) consists of a pair of concentric rings which vibrate at high frequency to rotate back and forth, an arrangement which permits the user to move the focus ring to directly move the lens element, achieving full time manual focus without damaging the motor. Stepper motors are better at producing smooth, precise incremental movements, such as those required by contrast detect AF, and AF during video. Ultrasonic motors are better at jumping to the right focus point as part of a phase detection system.
1661117
Greetings Georgina,Thank you for your interests in our item , and for contacting us regarding your concerns.We are pleased to inform you that the lens included in the kit is the original canon 18-55 StM Lens.As always, your satisfaction is our ultimate goal and we look forward to serving you again in the future. Should you have any additional questions or concerns, please do not hesitate to contact us again.Best Regards,LindaCustomer Service TeamSuperFinds
399067
I don't have the same camera ; you must read the camera instruction manual to see if lenses EF and EF-S are compatible with your model (in the Canon website you can read "... the camera is compatible with Canon STM lenses for smooth, quiet AF performance..." and the following website you can find every lenses for canon cameras : http://www.usa.canon.com/cusa/consumer/standard_display/Lens_Advantage_Select Sophie
247255
The Canon EF 35mm f/1.4L USM works very, very well with autofocus. The USM is for "UltraSonic Motor," Canon's way of advertising their very fast, very quiet autofocusing system. One major advantage of USM is that you can still focus manually on top of the autofocus, in case the camera was looking somewhere different from where you were looking at. That being said, "Complete manual focus" just means that you can turn autofocus completely off, and switch to manual focus only. Even when you do that, the lens will still communcate with the camera, and you lose none of the features of the lens/camera system other than being able to completely control the focus manually. Hope that helps!
2240581
Thank you Very much for your Help, what do you think about the Tamron 17-50mm f/2.8 XR Di II and the Canon EF-S 17-55mm f/2.8 IS USM? If you had the money for only one general purpose lens, wich one will you chose?
494445
Hi, for the SL1 I think you should get the EF-S 18-135 STM version. It's slightly sharper. Also, the 18-135 STM version is more versatile and has larger apertures on equivalent focal lengths versus the 18-135 non stm and 18-55.
176998
You can have a look on canon website for the specs but the lens that comes with this kit is the stm version which produces pretty sharp images for kit lens. Again there is a ton of reviews out there if you research. This lens is obviously not going to be better than L lenses if you do a comparative. So it's really about what situation and output you are shooting for.
1768508
I have no experience with the IS II lens. I have only used the STM lenses. As far as I know, the only improvement in the STM lens over the IS II lens is silent focusing. It's only useful for making videos. If you are going to use this lens for filming, I would definitely say buy the STM lens. If not, I would consider the IS II if any other specifications do not differ.
794474
The new STM lens is an inch shorter and adds a zoom lock and instant manual-focus override to the older 18-135mm EF-S IS lens, however manual focus is electronic. The focus ring isn't connected to anything, and there is a tiny time delay between when you move the ring and the lens moving. Another huge improvement from the older 18-135mm EF-S IS is that the zoom range from 24mm to 18mm has been spread-out on the zoom ring, so it's much easier to set precise wide-angle framing. On the old lens, it was very cramped at the wide end.
1561300
So now I am wondering just what I am missing with regards to buying this lens for use on a DSLR like the Canon EOS 5D versus the much more expensive "EF 70-300 f/4-5.6 IS USM for EOS SLR"???
124500
Jamie, I had the same question. Truth be told I don't have the Canon version. I am interning this summer with one of the nation's best commercial photographers and I asked him. He told me that the Canon lens is built a little better but he has both and he uses both. He told me I wouldn't be disappointed in this lens and I haven't been.
2240582
I've been using the 17-85mm IS USM with my cameras for several years - love it. I have not used this lens, but you can find the 17-85 used for several hundred dollars cheaper than the 17-40L and it is a more versatile lens.
1974695
This lens is a little noisy compared to Canon USM lenses, although not as much as an older Tamrom 17-50 I use with a 40D. If any doubts, you can always go a camera store nearby and try a display Tokina 16-28.
2085161
Yes. Canon does their best to make all their EOS cameras use the same lenses. Some features on new lenses (like the continuous AF of the STM lenses) won't work on the older bodies, but the lens will fit and work like any other lens you've used with single shot AF.
866658
55-250mm is not STM, but provides an image stabilizer (IS), not a bad lens to start with, then again it depends what you're using it for.
1495159
I agree with Wesley, for the most part. USM refers to Ultra Sonic Motor, which is a little bit quieter than the regular autofocus motor, but that's not its primary purpose. The USM is capable of Autofocusing a great deal faster than a regular lens. Side by side, you'll notice quite a difference in the amount of time the lens needs to focus. Now, I shoot wildlife photography of wild animals. For me, that time difference in crucial. You'll want that should you ever be shooting moving subjects, like animals or sports events, for example. You'll have to consider how you plan to use the lens, and decide if the additional speed is something you'll need.
1646078
Both lenses are excellent and brilliantly sharp. The Sigma is less expensive. The Canon focuses more quickly, a little, no macro lenses are fast. It should come down to what focal length you want. Canon offers an IS version of the macro. The stabilization is nice if you hand hold, but doubles the price and weight.